US-12618005-B2 - Light emitting element and manufacturing method thereof

Abstract

A light emitting element according to an embodiment includes a first electrode, a second electrode overlapping the first electrode, an emission layer disposed between the first electrode and the second electrode, and an electron transport region disposed between the emission layer and the second electrode, wherein the electron transport region includes a thermal acid generator (TAG). A method of manufacturing a light emitting element is also provided.

Inventors

• Sang Hee Yu
• Hoi-Lim KIM
• Jae Hong Park
• Gyu Bong Kim
• Seung Uk Noh
• Ju Yon LEE

Assignees

• SAMSUNG DISPLAY CO., LTD.

Dates

Publication Date

20260505

Application Date

20220609

Priority Date

20210610

Claims (16)

1. 1 . A light emitting element comprising: a first electrode; a second electrode overlapping the first electrode; an emission layer disposed between the first electrode and the second electrode; and an electron transport region disposed between the emission layer and the second electrode, wherein the electron transport region comprises a thermal acid generator (TAG) and inorganic nanoparticles, wherein the TAG generates H + upon thermal treatment, and wherein the H + is adsorbed on the inorganic nanoparticles, and wherein the inorganic nanoparticles comprise zinc oxide (ZnO).
2. 2 . The light emitting element of claim 1 , wherein the electron transport region comprises a material in which H + is separated from the TAG.
3. 3 . The light emitting element of claim 1 , wherein the TAG comprises a sulfonate-based compound.
4. 4 . The light emitting element of claim 3 , wherein the TAG comprises a compound represented by Chemical Formula 1: wherein in Chemical Formula 1, R 1 and R 2 are each independently a substituted or unsubstituted C3 to C40 alkyl group, a substituted or unsubstituted C3 to C40 aliphatic hydrocarbon group, a substituted or unsubstituted C6 to C40 aromatic hydrocarbon group of C6 to C40, or a combination thereof.
5. 5 . The light emitting element of claim 4 , wherein the compound represented by Chemical Formula 1 comprises at least one compound each independently represented by one of Chemical Formula 2-1, Chemical Formula 2-2, Chemical Formula 2 -3, Chemical Formula 2-4, Chemical Formula 2-5, Chemical Formula 2-6, Chemical Formula 2-7, Chemical Formula 2-8, Chemical Formula 3-1, Chemical Formula 3-2, Chemical Formula 3-3, Chemical Formula 3-4, Chemical Formula 3-5, and Chemical Formula 3-6:
6. 6 . The light emitting element of claim 1 , wherein the emission layer comprises quantum dots.
7. 7 . The light emitting element of claim 1 , wherein the first electrode is an anode, the second electrode is a cathode, and the electron transport region comprises at least one of a hole blocking layer, an electron transport layer, and an electron injection layer.
8. 8 . A method of manufacturing a light emitting element, comprising: forming a first electrode; forming an emission layer on the first electrode; forming an electron transport region on the emission layer; and forming a second electrode on the electron transport region, wherein the forming of the electron transport region comprises: applying a solution including inorganic nanoparticles and a thermal acid generator (TAG); and curing the solution, wherein the TAG generates H + upon thermal treatment, and wherein the H + is adsorbed on the inorganic nanoparticles, wherein in the curing of the solution, the TAG generates H + , wherein the H+ generated in the curing separates a branch part adsorbed on the inorganic nanoparticle.
9. 9 . The method of manufacturing the light emitting element of claim 8 , wherein the TAG comprises a sulfonate-based compound.
10. 10 . The method of manufacturing the light emitting element of claim 9 , wherein the TAG comprises a compound represented by Chemical Formula 1: wherein in Chemical Formula 1, R 1 and R 2 are each independently a substituted or unsubstituted C3 to C40 alkyl group, a substituted or unsubstituted C3 to C40 aliphatic hydrocarbon group, a substituted or unsubstituted C6 to C40 aromatic hydrocarbon group of C6 to C40, or a combination thereof.
11. 11 . The method of manufacturing the light emitting element of claim 9 , wherein the compound represented by Chemical Formula 1 comprises at least one compound each independently represented by one of Chemical Formula 2-1 to Chemical Formula 2-8:
12. 12 . The method of manufacturing the light emitting element of claim 9 , wherein the compound represented by Chemical Formula 1 comprises at least one compound each independently represented by one of Chemical Formula 3-1 to Chemical Formula 3-6:
13. 13 . The method of manufacturing the light emitting element of claim 9 , wherein the emission layer comprises quantum dots.
14. 14 . The method of manufacturing the light emitting element of claim 9 , wherein the curing is carried out at a first temperature in a range of about 100 degrees (° C.) to about 150 degrees (° C.).
15. 15 . The method of manufacturing the light emitting element of claim 14 , further comprising aging after the curing of the solution.
16. 16 . The method of manufacturing the light emitting element of claim 15 , wherein the aging is carried at a second temperature that is lower than the first temperature.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application claims priority to and benefits of Korean Patent Application No. 10-2021-0075389 under 35 U.S.C. § 119, filed on Jun. 10, 2021 in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. BACKGROUND 1. Technical Field The disclosure relates to a light emitting element and a manufacturing method thereof. 2. Description of the Related Art A light emitting element is an element in which electrical energy is converted into light energy. Examples of such a light emitting element include an organic light emitting element using an organic material for an emission layer, a quantum dot light emitting element using quantum dots for an emission layer, and the like. The light emitting element includes a first electrode disposed on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode that are sequentially disposed on the first electrode. Holes injected from the first electrode move to the emission layer via the hole transport region, and electrons injected from the second electrode move to the emission layer via the electron transport region. Carriers such as holes and electrons recombine in the emission layer to generate excitons. Light is generated as the excitons transition from an exited state to a ground state. It is to be understood that this background of the technology section is, in part, intended to provide useful background for understanding the technology. However, this background of the technology section may also include ideas, concepts, or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to a corresponding effective filing date of the subject matter disclosed herein. SUMMARY Embodiments provide a light emitting element with increased luminous efficiency and light emitting life-span through a TAG provided to an electron transport region and a manufacturing method thereof. According to an embodiment, a light emitting element may include a first electrode, a second electrode overlapping the first electrode, an emission layer disposed between the first electrode and the second electrode, and an electron transport region disposed between the emission layer and the second electrode, wherein the electron transport region may include a thermal acid generator (TAG). The electron transport region may include a first material in which H+ is separated from the TAG. The electron transport region may further include inorganic nanoparticles. The H+ may be bonded to the inorganic nanoparticles. The TAG may include a sulfonate-based compound. The TAG may include a compound represented by Chemical Formula 1: In Chemical Formula 1, R1 and R2 may each independently be a substituted or unsubstituted C3 to C40 alkyl group, a substituted or unsubstituted C3 to C40 aliphatic hydrocarbon group, a substituted or unsubstituted C6 to C40 aromatic hydrocarbon group of C6 to C40, or a combination thereof The compound represented by Chemical Formula 1 may include at least one compound each independently represented by one of Chemical Formula 2-1, Chemical Formula 2-2, Chemical Formula 2-3, Chemical Formula 2-4, Chemical Formula 2-5, Chemical Formula 2-6, Chemical Formula 2-7, Chemical Formula 2-8, Chemical Formula 3-1, Chemical Formula 3-2, Chemical Formula 3-3, Chemical Formula 3-4, Chemical Formula 3-5, and Chemical Formula 3-6: The emission layer may include quantum dot. The first electrode may be an anode, the second electrode may be a cathode, and the electron transport region may include at least one of a hole blocking layer, an electron transport layer, and an electron injection layer. According to an embodiment, a method of manufacturing a light emitting element may include forming a first electrode, forming an emission layer on the first electrode, forming an electron transport region on the emission layer, and forming a second electrode on the electron transport region, wherein the forming of the electron transport region may include applying a solution including inorganic nanoparticles and a thermal acid generator (TAG), and curing the solution. The TAG may include a sulfonate-based compound. The TAG may include a compound represented by Chemical Formula 1. The compound represented by Chemical Formula 1 may include at least one compound each independently represented by Chemical Formula 2-1 to Chemical Formula 2-8. The compound represented by Chemical Formula 1 may include at least one compound each independently represented by Chemical Formula 3-1 to Chemical Formula 3-6. The emission layer may include quantum dots. In the curing of the solution, the TAG may generate H+. The curing may be carried out at a first temperature in a range of about 100 degrees (° C.) to about 150 degrees (° C.). The method of manufacturing the light emitting element may further include aging after the curing the solution